Rotating fluid machine

ABSTRACT

In a rotating fluid machine, a high-pressure working medium introducing hole, for introducing high-temperature high-pressure steam to a slide surface, is opened to a fixed side valve plate. Therefore, when a single first high-pressure working medium passage which opens from the fixed side valve plate to the slide surface and a plurality of second high-pressure working medium passages which open from a movable side valve plate to the slide surface, sequentially communicate with each other with rotation of a rotor, the high-temperature high-pressure steam from the first high-pressure working medium passage and the high-temperature high-pressure steam from the high-pressure working medium introducing hole are uniformly introduced to the entirety of the slide surface, and a change in the surface pressure of the slide surface is suppressed to stabilize the behavior of the fixed side valve plate, thus preventing leakage of the high-temperature high-pressure steam and the occurrence of abnormal wear.

CROSS-REFERENCE TO RELATED APPLICATION

The present non-provisional application claims priority under 35 USC 119 to Japanese Patent Application No. 2003-401325 filed on Dec. 1, 2003 the entire contents thereof is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a rotating fluid machine including a casing, a rotor rotatably supported at the casing, a working section provided at the rotor, and a rotary valve which is provided between the casing and the rotor for controlling the supply and discharge of a working medium to and from the working section.

2. Description of the Related Art

A rotating fluid machine having a rotary valve including a fixed side valve plate supported at the casing side and a movable side valve plate supported at the rotor side which are in contact with each other on a slide surface is known, for example, as disclosed in Japanese Patent Application Laid Open No. 2002-256805. A steam supply passage and a steam discharge passage open to the slide surface of the fixed side valve plate; and a plurality of steam passages, which communicate with a plurality of expansion chambers of the rotor, open to the slide surface of the movable side valve plate equidistantly in the circumferential direction.

Accordingly, a high-temperature high-pressure steam, which is supplied from the steam supply passage of the fixed side valve plate to a predetermined steam passage of the movable side valve plate, expands in the expansion chamber to drive the piston. The resultant low-temperature low-pressure steam, which has finished expansion work, is discharged from the predetermined steam passage of the movable side valve plate to the steam supply/discharge passage of the fixed side valve plate. This operation is performed sequentially for each of the expansion chambers, thereby driving the rotor to rotate.

In the above-described rotary valve, a single high-pressure steam passage which opens to the slide surface of the fixed side valve plate sequentially communicates with a plurality of high-pressure steam passage which open to the slide surface of the movable side valve plate, and therefore the high-pressure steam passage at the fixed side valve plate and the high-pressure steam passage at the movable side valve plate alternately repeat communication and shutoff. Thus, the reaction force on the slide surface decreases at the time of communication, and the reaction force of the slide surface increases at the time of shutoff, so that the degree of contact by the slide surface periodically changes in the vicinity of the high-pressure steam passage of the fixed side valve plate. Thus, a disadvantageous problem arises that causes leakage of the high-temperature high-pressure steam from the slide surface and abnormal wear of the slide surface.

SUMMARY OF THE INVENTION

The present invention has been achieved in view of the above circumstances, wherein one object is to suppress change in the surface pressure of a slide surface of a rotary valve of a rotating fluid machine for preventing leakage of a working medium from a slide surface and for preventing the occurrence of abnormal wear on the slide surface.

In order to attain the above-described object, according to a first feature of the present invention, there is provided a rotating fluid machine including a casing; a rotor which is rotatably supported within the casing; a working section which is provided at the rotor; and a rotary valve which is provided between the casing and the rotor for controlling the supply and discharge of a working medium to and from the working section. The rotary valve includes a fixed side valve plate supported at the casing side and a movable side valve plate supported at the rotor side which are in contact with each other on a slide surface. A single first high-pressure working medium passage is provided which opens from the fixed side valve plate to the slide surface and a plurality of second high-pressure working medium passages are provided which open from the movable side valve plate to the slide surface, sequentially communicating with each other with the rotation of the rotor, wherein a high-pressure working medium introducing hole which introduces a high-pressure working medium to the slide surface is opened to the fixed side valve plate.

According to a second feature of the present invention, in addition to the first feature, the first high-pressure working medium passage and the high-pressure working medium introducing hole are disposed at equal angles in a circumferential direction.

According to a third feature of the present invention, in addition to the first or second feature, the high-pressure working medium which is introduced from the high-pressure working medium introducing hole to the slide surface is a high-pressure working medium which is supplied from the first high-pressure working medium passage to the second high-pressure working medium passage in an expansion stroke, or a high-pressure working medium which is discharged from the second high-pressure working medium passage in a compression stroke to the first high-pressure working medium passage.

In the present invention, an axial piston cylinder group A in one embodiment corresponds to the working section of the present invention, a second steam passage P2 of the embodiment corresponds to the first high-pressure working medium passage of the present invention, and a third steam passage P3 of the embodiment corresponds to the second high-pressure working medium passage.

With arrangement of the first feature, in the rotary valve in which the fixed side valve plate supported at the casing side and the movable side valve plate supported at the rotor side are brought into contact with each other on the slide surface, the high-pressure working medium introducing hole, which introduces the high-pressure working medium to the slide surface, is opened to the fixed side valve plate. Therefore, when the single first high-pressure working medium passage which opens to the slide surface from the fixed side valve plate, and the second high-pressure working medium passage which open to the slide surface from a movable side valve plate, communicate with each other sequentially with the rotation of a rotor, the high-pressure working medium from the first high-pressure working medium passage and the high-pressure working medium from the high-pressure working medium introducing hole are uniformly introduced to the entirety of the slide surface, and a change in the surface pressure of the slide surface is suppressed to stabilize the behavior of the fixed side valve plate, thus preventing the leakage of the working medium and the occurrence of abnormal wear. Even when the degree of sealing of the slide surface is especially enhanced in order to inhibit the leakage of the working medium, the slide surface is prevented from having solid lubrication by the introduced working medium, to thereby improve the wear resistance.

With the arrangement of the second feature, the first high-pressure working medium passage and the high-pressure working medium introducing hole are disposed at equal angles in the circumferential direction. Therefore, the high-pressure working medium which is introduced from the first high-pressure working medium passage and the high-pressure working medium which is introduced from the high-pressure working medium introducing hole are further uniformly supplied to the entirety of the slide surface, thus further stabilizing the behavior of the fixed side valve plate.

With the arrangement of the third feature, when the rotating fluid machine is an expander, the high-pressure working medium which is supplied from the first high-pressure working medium passage to the second high-pressure working medium passage in the expansion stroke can be introduced to the slide surface; and when the rotating fluid machine is a compressor, the high-pressure working medium which is discharged from the second high-pressure working medium passage in the compression stroke to the first high-pressure working medium passage can be introduced to the slide surface.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:

FIG. 1 is a longitudinal sectional view of an expander;

FIG. 2 is an enlarged view of the section 2 in FIG. 1;

FIG. 3 is an exploded perspective view of a rotor;

FIG. 4 is an enlarged view of the section 4 in FIG. 1;

FIG. 5 is a view taken along the line 5-5 in FIG. 4;

FIG. 6 is a view taken along the line 6-6 in FIG. 4;

FIG. 7 is a view taken along the line 7-7 in FIG. 4;

FIG. 8 is a view taken along the line 8-8 in FIG. 4; and

FIG. 9 is a perspective view of a coil spring, a packing retainer and a V packing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIG. 1 to FIG. 3, an expander E of this embodiment is used in, for example, a Rankine cycle system. The expander E converts the thermal energy and the pressure energy of high-temperature high-pressure steam as a working medium into mechanical energy that is outputted. A casing 11 of the expander E is formed from a casing body 12, a front cover 15 joined via a seal 13 to a front opening of the casing body 12 by a plurality of bolts 14, a rear cover 18 joined via a seal 16 to a rear opening of the casing body 12 by a plurality of bolts 17, and an oil pan 21 joined via a seal 19 to a lower opening of the casing body 12 by a plurality of bolts 20.

A rotor 22 is arranged rotatably around an axis L and extends in the fore-and-aft direction through the center of the casing 11 with a front part supported by combined angular bearings 23 provided in the front cover 15, and a rear part thereof supported by a radial bearing 24 provided in the casing body 12. A swash plate holder 28 is formed integrally with a rear face of the front cover 15. A swash plate 31 is rotatably supported by the swash plate holder 28 via an angular bearing 30. The axis of the swash plate 31 is inclined relative to the axis L of the rotor 22, and the angle of inclination is fixed.

The rotor 22 includes an output shaft 32 supported in the front cover 15 by the combined angular bearings 23, three sleeve support flanges 33, 34, and 35 formed integrally with a rear part of the output shaft 32, a rotor head 38 that is joined by a plurality of bolts 37 to the rear sleeve support flange 35 via a metal gasket 36 and is supported in the casing body 12 by the radial bearing 24, and a heat-insulating cover 40 that is fitted over the three sleeve support flanges 33, 34, and 35 from the front and joined to the front sleeve support flange 33 by a plurality of bolts 39.

Sets of five sleeve support holes 33 a, 34 a, and 35 a are formed in the three sleeve support flanges 33, 34, and 35 respectively at intervals of 72° around the axis L. Five cylinder sleeves 41 are fitted into the sleeve support holes 33 a, 34 a, and 35 a from the rear. A flange 41 a is formed on the rear end of each of the cylinder sleeves 41, and axial positioning is carried out by abutting this flange 41 a against the metal gasket 36 while fitting the flange 41 a into a step 35 b formed in the sleeve support holes 35 a of the rear sleeve support flange 35 (see FIG. 8). A piston 42 is slidably fitted within each of the cylinder sleeves 41, the front end of the piston 42 abutting against a dimple 31 a formed on the swash plate 31, and a steam expansion chamber 43 is defined between the rear end of the piston 42 and the rotor head 38.

Next, the structure of a rotary valve 71 which supplies and discharges steam to and from five expansion chambers 43 of the rotor 22 will be described with reference to FIG. 4 to FIG. 9.

As shown in FIG. 4, the rotary valve 71 disposed along the axis L of the rotor 22 includes a valve body portion 72, a fixed side valve plate 73 made of carbon, and a movable side valve plate 74 made of carbon, TEFLON®, metal or the like. In a state in which the movable side valve plate 74 is positioned by a knock pin 75 in the rotating direction on a rear surface of the rotor 22, the movable side valve plate 74 is fixed by a bolt 76 which is screwed into an oil passage closing member 45 (see FIG. 2). The bolt 76 also has a function of fixing the rotor head 38 to the output shaft 32.

In the valve body part 72, a circular flange 72 a, which is integrally formed at a rear portion of the valve body part 72, abuts to a rear surface of the rear cover 18 via a seal member 91, and is fixed by a plurality of bolts 92. In this case, a support portion 72 b with a circular section, which is integrally formed at a front portion of the valve body part 72, is fitted in a support hole 18 a of the rear cover 18. An annular holder 79 is fixed by a plurality of bolts 80 to a support surface 18 b leading to the support hole 18 a of the rear cover 18. The fixed side valve plate 73, which is held within the holder 79 via a seal member 82, is prevented from rotating by knock pins 81 and 81 coated with TEFLON®. The fixed side valve plate 73 is positioned in the rotating direction by the knock pins 81 and 81, but is floatingly supported to be slightly movable in the radial direction and the direction of the axis L.

A pressure chamber 84 with a circular section is opened to a mating surface 83 where the valve body part 72 abuts to the fixed side valve plate 73. A steam supply pipe 85, which penetrates through the valve body part 72 via a seal member 93, extends through a center of the pressure chamber 84 to reach the mating surface 83. Inside the pressure chamber 84, a coil spring 86, a packing retainer 87 and a V packing 88 are sequentially disposed on an outer periphery of the steam supply pipe 85.

A small gap is provided between a tip end of the steam supply pipe 85 and the mating surface 83 of the fixed side valve plate 73, so that even if the steam supply pipe 85 thermally expands in the direction of the axis L, the tip end does not interfere with the mating surface 83. One through-hole 85 a which is formed in the steam supply pipe 85 communicates with a rear part of the pressure chamber 84. The high-temperature high-pressure steam supplied to the pressure chamber 84 urges the fixed side valve plate 73 toward the movable side valve plate 74 to bring slide surfaces 77 of the valve plates 73 and 74 into close contact with each other, thereby exhibiting a function of improving the sealing performance. A plurality of through-hole 85 a may be provided in correspondence to the strength of the steam supply pipe 85 and the required steam supply amount to the pressure chamber 84.

As is obvious from FIG. 4 and FIG. 9, the packing retainer 87, which is urged by the coil spring 86 which are formed of a uniform diameter without tapering, includes a flat surface 87 a to which the coil spring 86 abuts, a conical surface 87 b which is formed on an opposite side from the flat surface 87 a, and a through-hole 87 c which is loosely fitted on an outer periphery of the steam supply pipe 85. Formed on the V packing 88 held by the packing retainer 87 are a conical surface 88 a which is supported on the conical surface 87 b of the packing retainer 87, a first seal lip S1 which seals a gap to the mating surface 83 of the fixed side valve plate 73, and a second seal lip S2 which seals a gap to an inner peripheral surface 84 a of the pressure chamber 84.

The V packing 88 has a main object of sealing the gap to the inner peripheral surface 84 a of the pressure chamber 84 so that the second seal lip S2 is deformed outwardly in a radial direction by the steam pressure of the pressure chamber 84 to be in close contact with the inner peripheral surface 84 a. Accordingly, the second seal lip S2 excellently follows the extension of the inner diameter of the inner peripheral surface 84 a of the pressure chamber 84 due to thermal expansion of the valve body section 72, to thereby ensure the sealing performance.

The coil spring 86 functions to provide a preliminary load to press the V packing 88 against the mating surface 83 via the fixed side valve plate 73 before the development of the pressure of the high-temperature high-pressure steam, and to dampen the vibration of the fixed side valve plate 73 in cooperation with the seal member 82 and the pressure of the high-temperature high-pressure steam in the pressure chamber 84. The packing retainer 87 functions to hold the V packing 88 in an appropriate posture inside the pressure chamber 84, and to enhance the durability of the V packing 88 by blocking the heat of the high-temperature high-pressure steam.

The coil spring 86 has a structure in which a spring seat is eliminated in order to secure a large number of winding of the spring in the small space inside the pressure chamber 84. The packing retainer 87 interposed between the coil spring 86 and the V packing 88 is used as a spring seat without causing the coil spring 86 to directly abut to the V packing 88. Therefore, a special spring seat is not needed to be provided in the V packing 88, and the size of the pressure chamber 84 is reduced in the direction of the axis L while securing the maximum length of the coil spring 86.

As is clear from FIG. 4 to FIG. 8, the steam supply pipe 85 is disposed on the axis L of the rotor 22. A steam discharge pipe 89 is disposed to be eccentrically positioned outwardly in the radial direction of the steam supply pipe 85. A first steam passage PI formed inside the steam supply pipe 85 communicates with the slide surface 77 via a second steam passage P2 formed in the fixed side valve plate 73. Five third-steam-passages P3, which are equidistantly disposed to surround the axis L, penetrate through the movable side valve plate 74. Opposite ends of five fourth-steam-passages P4, which are formed in the rotor 22 to surround the axis L, communicate respectively with the third steam passages P3 and the expansion chamber 43. While a portion at which the second steam passage P2 opens to the slide surface 77 is circular, a portion at which a fifth steam passage P5 opens to the slide surface 77 is formed into an arc shape with the axis L as the center.

On the slide surface 77 of the fixed side valve plate 73, the arc-shaped fifth steam passage P5 and two arc-shaped sixth steam passages P6 and P6, which communicate with one another, are each provided in a concave form. The sixth steam passage P6 and P6 communicate with seventh steam passages P7 and P7, which are formed in the valve body section 72, at the mating surface 83. A steam discharge chamber 94 is formed between the casing body 12 and the rear cover 18. The steam discharge chamber 94 communicates with the steam discharge pipe 89, and communicates with the seventh steam passages P7 and P7 which are formed in the valve body 72.

The circular second steam passage P2 for supplying the high-temperature high-pressure steam, and the arc-shaped fifth steam passage P5 for discharging low-temperature low-pressure steam are opened to the slide surface 77. An intake stroke starts at the moment when one of the five third-steam-passages P3 of the movable side valve plate 74 communicates with the circular second steam passage P2. An expansion stroke is performed from the time when the third steam passage P3 is shut off from the communication with the second steam passage P2 until the third steam passage P3 communicates with the arc-shaped fifth steam passage P5. An exhaust stroke is performed while the third steam passage P3 is communicating with the arc-shaped fifth steam passage P5.

As is obvious from FIG. 4, FIG. 6 and FIG. 7, two high-pressure working medium introduction passages 73 a and 73 a are opened to the mating surface 83 of the fixed side valve plate 73 of the rotary valve 71. The two high-pressure working medium introducing holes 73 b and 73 b which extend from bottom portion of the high-pressure working medium introducing passages 73 a and 73 a open to the slide surface 77 between the fixed side valve plate 73 and the movable side valve plate 74. The high-pressure working medium introducing passages 73 a and 73 a communicates with the steam supply pipe 85 via a gap between the packing retainer 87 and the fixed side valve plate 73, and therefore the high-temperature high-pressure steam from the steam supply pipe 85 is supplied from the gap to the slide surface 77 via the high-pressure working medium introducing passages 73 a and 73 a and the high-pressure working medium introducing holes 73 b and 73 b.

As is most clearly shown in FIG. 6, the two high-pressure working medium introducing holes 73 b and 73 b which open to the slide surface 77 of the fixed side valve plate 73, and the second steam passage P2 which opens to the slide surface 77 are disposed at equal angles, namely, at intervals of 120° in the circumferential direction with the axis L as the center. The positions in the radial direction of the two high-pressure working medium introducing holes 73 b and 73 b, which open to the slide surface 77, are closer to the axis L than the inner ends of the second steam passage P2 and the fifth steam passage P5 in the radial direction. Accordingly, even when the movable side valve plate 74 rotates with respect to the fixed side valve plate 73, the two high-pressure working medium introducing holes 73 b and 73 b do not communicate with the five third steam passages P3 which open to the slide surface 77 of the movable side valve plate 74.

Next, the operation of the expander E of the present embodiment with the above-described construction will be described.

The high-temperature high-pressure steam generated by heating water by a vaporizer passes through the first steam passage P in the steam supply pipe 85, the mating surface 83 and the second steam passage P2 of the fixed side valve plate 73, to reach the slide surface 77 of the movable side valve plate 74. The second steam passage P2 which opens to the slide surface 77 instantly communicates, at a predetermined timing, with the five third-steam-passages P3 formed in the movable side valve plate 74 which rotates integrally with the rotor 22, so that the high-temperature high-pressure steam passes from the third steam passage P3 through the fourth steam passage P4 formed in the rotor 22, to be supplied to the expansion chamber 43 in the cylinder sleeve 41.

Even after the communication between the second steam passage P2 and the third steam passage P3 is shut off with the rotation of the rotor 22, the high-temperature high-pressure steam expands in the expansion chamber 43, whereby the piston 42 fitted in the cylinder sleeve 41 is pushed forward from the top dead center to the bottom dead center, and the front end of the piston 42 presses the dimple 3 la of the swash plate 31. As a result, a rotation torque is given to the rotor 22 due to the reaction force which the piston 42 receives from the swash plate 31. Thus, every time the rotor 22 makes one-fifth of a turn, the high-temperature high-pressure steam is supplied into a new adjacent expansion chamber 43, thereby continuously driving the rotor 22 to rotate.

While the piston 42 having reached the bottom dead center with the rotation of the rotor 22 retreating to the top dead center by being pressed by the swash plate 31, the low-temperature low-pressure steam pushed out of the expansion chamber 43 is supplied to a condenser via the fourth steam passage P4 of the rotor 22, the third steam passage P3 of the movable side valve plate 74, the slide surface 77, the fifth steam passage P5 and the sixth steam passages P6 and P6 of the fixed side valve plate 73, the mating surface 83, the seventh steam passages P7 and P7 of the valve body section 72, the steam discharge chamber 94 and the steam discharge pipe 89.

The rotary valve 71 supplies and discharges steam to and from an axial piston cylinder group A via the flat slide surface 77 between the fixed side valve plate 73 and the movable side valve plate 74, thereby effectively preventing the leakage of the steam. This is because the flat slide surface 77 is easily machined with high precision and the control of the clearance is easier as compared with a cylindrical slide surface. In addition, when the pressure of the high-temperature high-pressure steam supplied to the expander E becomes high, the high-temperature high-pressure steam becomes likely to leak from the slide surface 77 of the fixed side valve plate 73 and the movable side valve plate 74, but the pressing load, which the pressure chamber 84 generates in accordance with the increase in the pressure, increases to enhance the surface pressure of the slide surface 77, thus exhibiting a sealing performance corresponding to the pressure of the high-temperature high-pressure steam.

Specifically, the high-temperature high-pressure steam is supplied from the second steam passage P2 of the fixed side valve plate 73 to the slide surface 77 between the fixed side valve plate 73 and the movable side valve plate 74; then supplied to the expansion chamber 43 at the moment when the second steam passage P2 communicates with any one of the five third-steam-passages P3 of the movable side valve plate 74; and when the second steam passage P2 does not communicates with any of the third steam passages P3, the high-temperature high-pressure steam is blocked at the slide surface 77. In this manner, communication and shutoff between the second steam passage P2 and the third steam passage P3 are repeatedly performed with the rotation of the movable side valve plate 74. At the time of communication, the steam pressure in the vicinity of the second steam passage P2 decreases and the surface pressure of the slide surface 77 increases, while at the time of shutoff, the steam pressure in the vicinity of the second steam passage P2 increases and the surface pressure of the slide surface 77 decreases.

Accordingly, the degree of contact between the fixed side valve plate 73 and the movable side valve plate 74 periodically changes in the vicinity of the second steam passage P2, leading to a possibility of leakage of the high-temperature high-pressure steam from the slide surface 77 and the abnormal wear of the slide surface 77.

However, according to this embodiment, the second steam passage P2 and the two high-pressure working medium introducing holes 73 b and 73 b open to the slide surface 77 of the fixed side valve plate 73, at equal angles in the circumferential direction. Therefore, the high-temperature high-pressure steam that is uniformly supplied from the second steam passage P2 and the two high-pressure working medium introducing holes 73 b and 73 b to the entirety of the slide surface 77; stabilizes the behavior of the fixed side valve plate 73 which is supported in a floating state; and suppresses the leakage of the high-temperature high-pressure steam and abnormal wear of the slide surface 77. Especially because steam is used as the working medium, water in the liquefied steam exists on the slide surface 77, thereby significantly enhancing the lubricating performance, cooling performance, sealing performance and the like of the slide surface 77, to contribute to an enhancement of the durability of the rotary valve 71. Even when the sealing performance of the slide surface 77 is especially enhanced in order to inhibit the leakage of the high-temperature high-pressure steam, the slide surface 77 is prevented from having solid lubrication, thereby enhancing wear resistance.

The embodiment of the present invention has been described, but various changes in design can be made without departing from the subject matter of the invention.

For example, the expander E of the embodiment includes the axial piston cylinder group A as the working section, but the structure of the working section is not limited thereto.

The rotating fluid machine of the present invention is not limited to the expander E, and can be applied to a compressor. When the rotating fluid machine is the expander E, the high-pressure working medium introduced from the high-pressure working medium introducing holes 73 b and 73 b to the slide surface 77 is the high-pressure working medium which is supplied from the second steam passage P2 to the third steam passages P3 in the expansion stroke. When the rotating fluid machine is a compressor, the high-pressure working medium introduced from the high-pressure working medium introducing holes 73 b and 73 b to the slide surface 77 is the high-pressure working medium which is discharged from the third steam passages P3 in the compression stroke to the second steam passage P2.

In this embodiment, the fixed side valve plate 73 includes the two high-pressure working medium introducing holes 73 b and 73 b, but the number of the high-pressure working medium introducing holes 73 b is optional.

In this embodiment, the high-pressure working medium introducing holes 73 b and 73 b are opened further inward in the radial direction from the inner ends in the radial direction of the second steam passage P2 and the fifth steam passage P5, but the high-pressure working medium introducing holes 73 b and 73 b may be opened further outwardly in the radial direction from the outer end in the radial direction of the second steam passage P2 and the fifth steam passage P5.

The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. 

1. A rotating fluid machine comprising: a casing; a rotor rotatably supported by the casing; a working section provided in the rotor; and a rotary valve provided between the casing and the rotor for controlling the supply and discharge of a working medium to and from the working section, the rotary valve having a fixed side valve plate supported at the casing side and a movable side valve plate supported at the rotor side which are in contact with each other on a slide surface, a single first high-pressure working medium passage which opens from the fixed side valve plate to the slide surface and a plurality of second high-pressure working medium passages which open from the movable side valve plate to the slide surface, sequentially communicating with each other with rotation of the rotor, and a high-pressure working medium introducing hole for introducing a high-pressure working medium to the slide surface being opened to the fixed side valve plate.
 2. The rotating fluid machine according to claim 1, wherein the first high-pressure working medium passage and the high-pressure working medium introducing hole are disposed at equal angles in a circumferential direction.
 3. The rotating fluid machine according to claim 1, wherein the high-pressure working medium which is introduced from the high-pressure working medium introducing hole to the slide surface is a high-pressure working medium which is supplied from the first high-pressure working medium passage to the second high-pressure working medium passage in an expansion stroke, or a high-pressure working medium which is discharged from the second high-pressure working medium passage in a compression stroke to the first high-pressure working medium passage.
 4. The rotating fluid machine according to claim 2, wherein the high-pressure working medium which is introduced from the high-pressure working medium introducing hole to the slide surface is a high-pressure working medium which is supplied from the first high-pressure working medium passage to the second high-pressure working medium passage in an expansion stroke, or a high-pressure working medium which is discharged from the second high-pressure working medium passage in a compression stroke to the first high-pressure working medium passage.
 5. The rotating fluid machine according to claim 2, wherein the first high-pressure working medium passage is disposed in a first position on said fixed side valve plate and two high-pressure working medium introducing holes are disposed at equal angles in a circumferential direction for stabilizing the fixed side valve plate.
 6. The rotating fluid machine according to claim 5, wherein said fixed side valve plate is supported in a floating state and further including a pressure chamber for biasing said fixed side valve plate into contact with said movable side valve plate.
 7. The rotating fluid machine according to claim 6, and further including a high-pressure supply operatively connected to said pressure chamber and being spaced a predetermined distance relative to said fixed side valve plate for supplying pressure to said first high-pressure working medium passage.
 8. The rotating fluid machine according to claim 7, and further including a packing retainer operatively positioned relative to said high-pressure supply and the fixed side valve plate for sealing the space therebetween.
 9. The rotating fluid machine according to claim 8, wherein said packing retainer includes a conical surface and further including a V-packing disposed adjacent to said conical surface for providing two sealing lips for sealing said space between the high-pressure supply and the fixed side valve plate.
 10. A valve for use in a rotating fluid machine comprising: a rotary valve adapted to be provided between a casing and a rotor for controlling the supply and discharge of a working medium to and from a working section of the rotor, a fixed side valve plate adapted to be supported at a casing side; a movable side valve plate adapted to be supported at a rotor side, said fixed side valve plate and said movable side valve plate being in contact with each other with a slide surface formed therebetween; a single first high-pressure working medium passage opening from the fixed side valve plate to the slide surface; a plurality of second high-pressure working medium passages opening from the movable side valve plate to the slide surface, said single first high-pressure working medium passage and said plurality of second high-pressure working medium passages being sequentially brought into communicating with each other with rotation of the rotor; and a high-pressure working medium introducing hole for introducing a high-pressure working medium to the slide surface is in communication with the fixed side valve plate for stabilizing the fixed side valve plate.
 11. The valve for use in a rotating fluid machine according to claim 10, wherein the first high-pressure working medium passage and the high-pressure working medium introducing hole are disposed at equal angles in a circumferential direction.
 12. The valve for use in a rotating fluid machine according to claim 10, wherein the high-pressure working medium which is introduced from the high-pressure working medium introducing hole to the slide surface is a high-pressure working medium which is supplied from the first high-pressure working medium passage to the second high-pressure working medium passage in an expansion stroke, or a high-pressure working medium which is discharged from the second high-pressure working medium passage in a compression stroke to the first high-pressure working medium passage.
 13. The valve for use in a rotating fluid machine according to claim 11, wherein the high-pressure working medium which is introduced from the high-pressure working medium introducing hole to the slide surface is a high-pressure working medium which is supplied from the first high-pressure working medium passage to the second high-pressure working medium passage in an expansion stroke, or a high-pressure working medium which is discharged from the second high-pressure working medium passage in a compression stroke to the first high-pressure working medium passage.
 14. The valve for use in a rotating fluid machine according to claim 11, wherein the first high-pressure working medium passage is disposed in a first position on said fixed side valve plate and two high-pressure working medium introducing holes are disposed at equal angles in a circumferential direction for stabilizing the fixed side valve plate.
 15. The valve for use in a rotating fluid machine according to claim 14, wherein said fixed side valve plate is supported in a floating state and further including a pressure chamber for biasing said fixed side valve plate into contact with said movable side valve plate.
 16. The valve for use in a rotating fluid machine according to claim 15, and further including a high-pressure supply operatively connected to said pressure chamber and being spaced a predetermined distance relative to said fixed side valve plate for supplying pressure to said first high-pressure working medium passage.
 17. The valve for use in a rotating fluid machine according to claim 16, and further including a packing retainer operatively positioned relative to said high-pressure supply and the fixed side valve plate for sealing the space therebetween.
 18. The valve for use in a rotating fluid machine according to claim 17, wherein said packing retainer includes a conical surface and further including a V-packing disposed adjacent to said conical surface for providing two sealing lips for sealing said space between the high-pressure supply and the fixed side valve plate. 